actually I think that is another part of problem, people try treat coco as it's soil and it's just not....beneficial bact, should be added to coco grow, very rarely do ya ever have to flush, unless somehow come up with an issue... the flush I refer to is before there has been any plant set in the coco and if your totally controlling the grow, like I do then none of that will be an issue..I wouldn't think there would be any bact in a brick of coco, i'd sure hope not, it's dry as shit am not sure how anything could survive that...